Function createRedirectResponse

packages/angular/ssr/src/utils/redirect.ts:35–73

(
  location: string,
  status = 302,
  headers?: Record<string, string> | Headers,
)

 * @returns A `Response` object representing the HTTP redirect.
 */
export function createRedirectResponse(
  location: string,
  status = 302,
  headers?: Record<string, string> | Headers,
): Response {
  if (ngDevMode && !isValidRedirectResponseCode(status)) {
    throw new Error(
      `Invalid redirect status code: ${status}. ` +
        `Please use one of the following redirect response codes: ${[...VALID_REDIRECT_RESPONSE_CODES.values()].join(', ')}.`,
    );
  }

  const resHeaders = headers instanceof Headers ? headers : new Headers(headers);
  if (ngDevMode && resHeaders.has('location')) {
    // eslint-disable-next-line no-console
    console.warn(
      `Location header "${resHeaders.get('location')}" will be ignored and set to "${location}".`,
    );
  }

  // Ensure unique values for Vary header
  const varyArray = resHeaders.get('Vary')?.split(',') ?? [];
  const varySet = new Set(['X-Forwarded-Prefix']);
  for (const vary of varyArray) {
    const value = vary.trim();

    if (value) {
      varySet.add(value);
    }
  }

  resHeaders.set('Vary', [...varySet].join(', '));
  resHeaders.set('Location', location);

  return new Response(null, {
    status,
    headers: resHeaders,
  });
}